A phase 2a clinical trial has found the dapivirine vaginal ring to be a safe and acceptable means for HIV prevention in adolescents, who showed notably high adherence when using the ring.
To put an end to the AIDS epidemic, researchers are working on findings more ways to prevent infection in populations that are at particularly high risk. One such population is adolescent girls and young women who are between the ages of 15 and 24.
In fact, the National Institutes of Allergy and Infectious Diseases (NIAID) reports that this group alone accounted for 20% of new infections among adults worldwide in 2015, even though they only accounted for 11% of the adult population.
To address these large numbers, preventive efforts tailored specifically for this population are needed. To this end, two teams of investigators reported findings from 2 different studies that focused on preventing HIV specifically in adolescents: a monthly vaginal ring and a daily oral tablet. The research was presented at the recent 9th International AIDS Conference on HIV Science. This article will focus on the trial for the vaginal ring; the first time that the ring had been tested in adolescent girls who were younger than 18 years of age.
A previous study, ASPIRE, which evaluated the safety and efficacy of a dapivirine vaginal ring as a means of HIV prevention in women between the ages of 18 and 45, found that the ring provided 27% of protection overall, but no protection in women between the ages of 18 and 21; researchers postulated that the reason for this was poor adherence to the regimen. A follow-up analysis yielded more promising results: by adhering to the ring, women reduced their risk of infection by a promising 56%.
Investigators decided to test this means of prevention in adolescent girls in the phase 2a clinical trial they dubbed MTN-023/IPM 030 to see if it could be a safe and effective option for this population as well. They enrolled a total of 96 sexually-active girls between the ages of 15 and 17 at 6 different sites in the United States. The girls were randomly assigned to 1 of 2 groups: a group that would receive the dapivirine ring or a group that would receive a placebo ring. They were instructed to insert a new ring on a monthly basis for the duration of 6 months. During this time, the investigators kept an eye on the amount of dapivirine in their blood as well as in the used ring to guage how well the participants were adhering to their regimens.
The ring was deemed safe and acceptable in adolescents, and, the results were favorable: adherence to the ring was high— “drug levels in 87% of blood samples and 95% of used rings met prespecified adherence criteria.” Furthermore, a whopping 93% of participants reported to like the ring; the common concerns involved keeping the ring clean and worry that their sexual partners might feel it during sexual intercourse.
“We are encouraged by these results of the dapivirine ring in 15- to 17-year olds,” Sharon Hillier, PhD, principal investigator of the NIH-funded Microbicide Trials Network (MTN), said in the press release. “The study has demonstrated that the ring is safe in US teens, and now we need data on the safety and acceptability of the ring in African adolescent girls. The REACH study, scheduled to launch later this year, will generate this data.”
For the REACH study, the investigators aim to gage the safety and efficacy of the dapivirine ring and the use of oral Truvada as pre-exposure prophylaxis among African adolescent girls and young women between the ages of 16 and 21. In addition, the researchers will evaluate how participants use the 2 preventive methods and what their preferences are for both approaches.
Feature Picture Source: National Institutes of Health